From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D3FBC19F2A for ; Mon, 8 Aug 2022 01:34:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C14588E0002; Sun, 7 Aug 2022 21:34:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BC4608E0001; Sun, 7 Aug 2022 21:34:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A8CFB8E0002; Sun, 7 Aug 2022 21:34:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 9B42C8E0001 for ; Sun, 7 Aug 2022 21:34:23 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 7A8D280939 for ; Mon, 8 Aug 2022 01:34:23 +0000 (UTC) X-FDA: 79774705206.19.12EACAA Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf02.hostedemail.com (Postfix) with ESMTP id 0EDE280018 for ; Mon, 8 Aug 2022 01:34:22 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8993E60CF6; Mon, 8 Aug 2022 01:34:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FBD6C433D6; Mon, 8 Aug 2022 01:34:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659922460; bh=0/Kxnd+QUuc9UVG//nKSwl1HMXqNHbK9ICtv8Ir5lfY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qIyQ06DEoHAUekO7mBsCA93pfVQ7tHFwuF1dAJOhjOFfKM7TqBIyGVg2TeYBCTHV4 eBD5UAPKwvpKWOd+lkJkgawIt2b3TTwAo9Qpnui7489zi/llzg6YQyBFw/hRsPu/bl bItcsgeWrEP3SYttQwBfSyOKWF5kUWC7ek+24XGK6nehRn1LoyNYZr6dYDGLKV87dZ RlZ0IuczBcgNrlZvca46qHAaNTxglm6Wz0bHTBkF5Ut12S+mdeHpyL1MIgC65J89pe iEJLKPZDOp/fsYN3jBI/GgVaPQnR1WDdZp5c4RFO2Is/j7BEQoB5E0RVZB+BvWO2TT TnVexCNaM6ITQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Catalin Marinas , Andrey Konovalov , Andrey Ryabinin , Vincenzo Frascino , Will Deacon , Sasha Levin , kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.18 08/53] mm: kasan: Ensure the tags are visible before the tag in page->flags Date: Sun, 7 Aug 2022 21:33:03 -0400 Message-Id: <20220808013350.314757-8-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220808013350.314757-1-sashal@kernel.org> References: <20220808013350.314757-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1659922463; a=rsa-sha256; cv=none; b=tL7m6V1L5oVxoEF1k6JpPw07s/FXDOdX/SiaiTUX8vA395Zzi2dOfvM+BO0tQlpTxlpmDr QfsWdUM6xLuJSIK4aGHry3cRKd22w9ajknLwNpulLY7wWG5Cwn8b42RIJWkc7SNrzh4bmn KGD4trHxn9ohXTzxGDiuMUfkMOOZWXo= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=qIyQ06DE; spf=pass (imf02.hostedemail.com: domain of sashal@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1659922463; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4VOGKjNvxfdZgBDKksD0XWodTGLWtey/jHGu5uBXZZ4=; b=dFeU4/UGytcpRCCEcU5s+tLTpd5B5dUQqO0BKiAQYmEcnJSJN3JWj0BUX7oiKxjpPk+GJA FiK4rz/F7G+l3sEoEf3hmsp7Nk3XMRS4An0lWsCttqlqMsCPc+yzn1Pct4TnGk7KZfk59s xFiQ1SRM6Y1KKdCjHcS5VQrSnkzLpoI= X-Stat-Signature: aid75ysi9yxzk475jw7uu3niwjefoagp X-Rspamd-Queue-Id: 0EDE280018 Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=qIyQ06DE; spf=pass (imf02.hostedemail.com: domain of sashal@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sashal@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1659922462-26952 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Catalin Marinas [ Upstream commit ed0a6d1d973e9763989b44913ae1bd2a5d5d5777 ] __kasan_unpoison_pages() colours the memory with a random tag and stores it in page->flags in order to re-create the tagged pointer via page_to_virt() later. When the tag from the page->flags is read, ensure that the in-memory tags are already visible by re-ordering the page_kasan_tag_set() after kasan_unpoison(). The former already has barriers in place through try_cmpxchg(). On the reader side, the order is ensured by the address dependency between page->flags and the memory access. Signed-off-by: Catalin Marinas Reviewed-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Vincenzo Frascino Reviewed-by: Vincenzo Frascino Link: https://lore.kernel.org/r/20220610152141.2148929-2-catalin.marinas@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- mm/kasan/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index d9079ec11f31..f6b8dc4f354b 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -108,9 +108,10 @@ void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init) return; tag = kasan_random_tag(); + kasan_unpoison(set_tag(page_address(page), tag), + PAGE_SIZE << order, init); for (i = 0; i < (1 << order); i++) page_kasan_tag_set(page + i, tag); - kasan_unpoison(page_address(page), PAGE_SIZE << order, init); } void __kasan_poison_pages(struct page *page, unsigned int order, bool init) -- 2.35.1